A major deficiency of compression molded thermoset glass fiber reinforced polyester (FRP) moldings is surface imperfections such as pits, pores, surface cracks, waviness, and sink marks. Another deficiency is surface cracks that can develop at low bending strains.
U.S. Pat. No. 4,515,710 describes an in-mold coating composition that is free radically cured to create a thermoset coating having good adhesion to the thermoset substrate, good surface smoothness, and good paintability.
U.S. Pat. No. 4,242,415 describes another in-mold coating composition containing amine-terminated reactive liquid polymers, a vinyl monomer, and crosslinkable ester urethane resins.
It is the object of this invention to provide a vinyl ester resin composition with telechelic flexible polymers or AB, ABA, or A(BA).sub.n block copolymers having flexible segments (B). These compositions with flexible segments have greater strain to failure and thus maintain good surface quality after deformation of the coated part.